Organic light-emitting device

ABSTRACT

An organic light-emitting device including: a first electrode; a second electrode facing the first electrode; a first emission unit and a second emission unit between the first electrode and the second electrode; and a first charge generation layer between the first emission unit and the second emission unit; wherein the first emission unit includes a first emission layer and a first inorganic buffer layer, and the second emission unit includes a second emission layer and a second inorganic buffer layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.16/417,426, filed May 20, 2019, which is a continuation of U.S. patentapplication Ser. No. 16/005,169, filed Jun. 11, 2018, now U.S. Pat. No.10,305,059, issued May 28, 2019, which is a continuation of U.S. patentapplication Ser. No. 15/173,336, filed Jun. 3, 2016, now U.S. Pat. No.9,997,733, issued Jun. 12, 2018, which claims priority to and thebenefit of Korean Patent Application No. 10-2015-0150266, filed Oct. 28,2015, the entire content of all of which is incorporated herein byreference.

BACKGROUND 1. Field

One or more aspects of example embodiments of the present disclosure arerelated to an organic light-emitting device.

2. Description of the Related Art

Organic light-emitting devices are self-emission devices that have wideviewing angles, high contrast ratios, short response times, and/orexcellent brightness, driving voltage, and/or response speedcharacteristics, and may produce full-color images.

An organic light-emitting device may include a first electrode on asubstrate, and a hole transport region, an emission layer, an electrontransport region, and a second electrode sequentially positioned on thefirst electrode. Holes provided from the first electrode may move towardthe emission layer through the hole transport region, and electronsprovided from the second electrode may move toward the emission layerthrough the electron transport region. Carriers (such as holes andelectrons) may recombine in the emission layer to produce excitons.These excitons may change (e.g., transition or radiatively decay) froman excited state to the ground state to thereby generate light.

SUMMARY

One or more aspects of example embodiments of the present disclosure aredirected toward an organic light-emitting device having high efficiencyand a long lifespan.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

One or more example embodiments of the present disclosure provide anorganic light-emitting device including:

a first electrode;

a second electrode facing the first electrode;

a first emission unit and a second emission unit between the firstelectrode and the second electrode; and

a first charge generation layer between the first emission unit and thesecond emission unit;

wherein the first emission unit includes a first emission layer and afirst inorganic buffer layer, and the second emission unit includes asecond emission layer and a second inorganic buffer layer.

BRIEF DESCRIPTION OF THE DRAWING

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the drawing, which is a schematic cross-sectionaldiagram illustrating the structure of an organic light-emitting deviceaccording to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in more detail to embodiments, examples ofwhich are illustrated in the accompanying drawing, wherein likereference numerals refer to like elements throughout, and duplicativedescriptions thereof may not be provided. In this regard, the presentembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein. Accordingly, theembodiments are merely described below, by referring to the drawing, toexplain aspects of the present description. Expressions such as “atleast one of”, “one of”, “selected from”, “at least one selected from”,and “one selected from”, when preceding a list of elements, modify theentire list of elements and do not modify the individual elements of thelist.

The thicknesses of layers, films, panels, regions, etc., may beexaggerated in the drawings for clarity. It will be understood that whenan element such as a layer, film, region, or substrate is referred to asbeing “on” another element, it can be directly on the other element orintervening element(s) may also be present. In contrast, when an elementis referred to as being “directly on” another element, no interveningelements are present.

The drawing is a schematic cross-sectional diagram illustrating thestructure of an organic light-emitting device 10 according to anembodiment of the present disclosure. The organic light-emitting device10 includes a first electrode 110, a first emission unit 130, a firstcharge generation layer 150, a second emission unit 170, and a secondelectrode 190.

In the organic light-emitting device 10, the first electrode 110 may bean anode, and the second electrode 190 may be a cathode.

In one embodiment, the organic light-emitting device 10 may have astructure including: a first electrode 110; a second electrode 190facing the first electrode 110; a first emission unit 130 and a secondemission unit 170 between the first electrode 110 and the secondelectrode 190; and a first charge generation layer 150 between the firstemission unit 130 and the second emission unit 170, wherein the firstemission unit 130 may include a first emission layer and a firstinorganic buffer layer, and the second emission unit 170 may include asecond emission layer and a second inorganic buffer layer.

In some embodiments, the first emission unit 130 may further include afirst hole injection layer between the first emission layer and thefirst electrode 110, and the first inorganic buffer layer may be betweenthe first emission layer and the first hole injection layer; the secondemission unit 170 may further include a second hole injection layerbetween the second emission layer and the first charge generation layer150, and the second inorganic buffer layer may be between the secondemission layer and the second hole injection layer.

For example, the first inorganic buffer layer may be directly in contactwith the first emission layer, and the second inorganic buffer layer maybe directly in contact with the second emission layer.

Hereinafter, a structure and a method of manufacturing the organiclight-emitting device 10 according to an embodiment of the presentdisclosure will be described with reference to the drawing.

A substrate may be under the first electrode 110 and/or above the secondelectrode 190. The substrate may be a glass substrate or a transparentplastic substrate, each having excellent mechanical strength, thermalstability, transparency, surface smoothness, ease of handling, and/orwater-resistance.

The first electrode 110 may be formed by, for example, depositing and/orsputtering a material for forming the first electrode 110 on thesubstrate. The first electrode 110 may be an anode, and in this case,the material for forming the first electrode 110 may be selected frommaterials with a high work function to facilitate hole injection. Thefirst electrode 110 may be a reflective electrode, a semi-transmissiveelectrode, or a transmissive electrode. The material for forming thefirst electrode 110 may be a transparent and/or highly conductivematerial (such as indium tin oxide (ITO), indium zinc oxide (IZO), tinoxide (SnO₂), and/or zinc oxide (ZnO)). When the first electrode 110 isa semi-transmissive electrode or a reflective electrode, the materialfor forming the first electrode 110 may include at least one selectedfrom magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium(Ca), magnesium-indium (Mg—In), and magnesium-silver (Mg—Ag).

The first electrode 110 may have a single-layer structure or amulti-layer structure including a plurality of layers. For example, thefirst electrode 110 may have a three-layered structure of ITO/Ag/ITO,but embodiments of the structure are not limited thereto.

The first emission unit 130, the first charge generation layer 150, andthe second emission unit 170 may be sequentially stacked in this statedorder on the first electrode 110.

The first charge generation layer 150 may control or manage the chargebalance between the first emission unit 130 and the second emission unit170, which are adjacent to one another. In this regard, the first chargegeneration layer 150 may be also referred to as an intermediateconnector layer (ICL).

The first charge generation layer 150 may be between the first emissionunit 130 and the second emission unit 170. As used herein, the term“adjacent” may refer to a case in which two layers are physically incontact with each other, or a case in which an undescribed layer isbetween the two layers.

In some embodiments, the first charge generation layer 150 may includean n-charge generation layer and a p-charge generation layer. Then-charge generation layer may include an n-type dopant, and the p-chargegeneration layer may include a p-type dopant. The n-charge generationlayer may be positioned closer to the first electrode 110 than thep-charge generation layer.

The first emission unit 130 may include a first emission layer and afirst inorganic buffer layer, and the second emission unit 170 mayinclude a second emission layer and a second inorganic buffer layer.

The first and second inorganic buffer layers may each include a metalhalide.

For example, the first and second inorganic buffer layers may eachinclude at least one halide compound selected from an alkali metalhalide, an alkaline earth metal halide, a transition metal halide, apost-transition metal halide, and a lanthanum-based metal halide.

In some embodiments, the first and second inorganic buffer layers mayeach include at least one iodide compound selected from an alkali metaliodide, an alkaline earth metal iodide, a transition metal iodide, apost-transition metal iodide, and a lanthanum-based metal iodide.

In some embodiments, the first and second inorganic buffer layers mayeach include at least one iodide compound selected from a lithium (Li)iodide, a sodium (Na) iodide, a potassium (K) iodide, a rubidium (Rb)iodide, a cesium (Cs) iodide, a beryllium (Be) iodide, a Mg iodide, a Caiodide, a strontium (Sr) iodide, a barium (Ba) iodide, a ytterbium (Yb)iodide, a samarium (Sm) iodide, a copper (Cu) iodide, a thallium (TI)iodide, a Ag iodide, a cadmium (Cd) iodide, a mercury (Hg) iodide, a tin(Sn) iodide, a lead (Pb) iodide, a bismuth (Bi) iodide, a zinc (Zn)iodide, a manganese (Mn) iodide, an iron (Fe) iodide, a cobalt (Co)iodide, a nickel (Ni) iodide, an Al iodide, an indium (In) iodide, agallium (Ga) iodide, a thorium (Th) iodide, and a uranium (U) iodide,but embodiments of the first and second inorganic buffer layers are notlimited thereto.

In some embodiments, the first and second inorganic buffer layers mayeach include at least one iodide compound selected from LiI, NaI, KI,RbI, CsI, BeI₂, MgI₂, CaI₂, SrI₂, BaI₂, YbI, YbI₂, YbI₃, SmI₃, CuI, TlI,AgI, CdI₂, HgI₂, SnI₂, PbI₂, BiI₃, ZnI₂, MnI₂, FeI₂, CoI₂, NiI₂, AlI₃,InI₃, GaI₃, ThI₄, and UI₃, but embodiments of the first and secondinorganic buffer layers are not limited thereto.

In some embodiments, the first and second inorganic buffer layers mayeach include a metal halide.

In some embodiments, the first and second inorganic buffer layers mayeach include at least one halide compound selected from an alkali metalhalide, an alkaline earth metal halide, a transition metal halide, apost-transition metal halide, and a lanthanum-based metal halide, andmay further include at least one metal. However, embodiments of thefirst and second inorganic buffer layers are not limited thereto.

For example, the first and second inorganic buffer layers may eachfurther include at least one metal selected from an alkali metal, analkaline earth metal, a transition metal, a post-transition metal, and alanthanum-based metal, but embodiments of the first and second inorganicbuffer layers are not limited thereto.

In some embodiments, the first and second inorganic buffer layers mayeach further include at least one metal selected from Li, Na, K, Rb, Cs,Be, Mg, Ca, Sr, Ba, Yb, Sm, Cu, TI, Ag, Cd, Hg, Sn, Pb, Bi, Zn, Mn, Fe,Co, Ni, Al, In, Ga, Th, and U.

In some embodiments, the first and second inorganic buffer layers mayeach include a metal halide and a metal.

For example, the first and second inorganic buffer layers may eachinclude a halide compound of a first metal in addition to a secondmetal, wherein the first metal is identical to the second metal.

In some embodiments, the first and second inorganic buffer layers mayeach include a halide compound of a first metal in addition to a secondmetal, wherein the first metal is different from the second metal.

The first and second inorganic buffer layers may each have a thicknessof about 1 nm to about 20 nm, and in some embodiments, about 5 nm toabout 10 nm. When the thicknesses of the first and second inorganicbuffer layers are within these ranges, the organic light-emitting device10 may achieve high efficiency.

In some embodiments, the organic light-emitting device 10 may furtherinclude a third emission unit between the first electrode 110 and thesecond electrode 190, and a second charge generation layer between thesecond emission unit 170 and the third emission unit. The third emissionunit may include a third emission layer and a third inorganic bufferlayer, and the third inorganic buffer layer may include at least oneiodide compound selected from an alkali metal iodide, an alkaline earthmetal iodide, a transition metal iodide, a post-transition metal iodide,and a lanthanum-based metal iodide.

In some embodiments, the first emission unit 130 may further include afirst electron transport region between the first emission layer and thefirst charge generation layer 150, and the second emission unit 170 mayfurther include a second electron transport region between the secondemission layer and the second electrode 190.

The first emission unit 130 may include the first emission layer, thefirst inorganic buffer layer, and an organic layer; and the secondemission unit 170 may include the second emission layer, the secondinorganic buffer layer, and an organic layer.

The organic light-emitting device 10 may include the first emission unit130 and the second emission unit 170 between the first electrode 110 andthe second electrode 190, and the first charge generation layer 150between the first emission unit 130 and the second emission unit 170,wherein the first emission unit 130 may include the first emission layerand the first inorganic buffer layer, and the second emission unit 170may include the second emission layer and the second inorganic bufferlayer.

In the organic light-emitting device 10, the first emission unit 130 mayinclude a first hole transport layer, and the second emission unit 170may include a second hole transport layer.

In the organic light-emitting device 10, the first emission unit 130 mayinclude a first inorganic buffer layer, and the second emission unit 170may include a second inorganic buffer layer. In this regard, duringmovement of holes from the first hole transport layer to the firstemission layer and holes from the second hole transport layer to thesecond emission layer, an undesirable flow of electrons may be blockedor reduced, thereby preventing or reducing recombination of the holesand the electrons in non-emission layers, thereby preventing or reducingdeterioration of materials, and increasing the efficiency of the organiclight-emitting device 10. In some embodiments, the first inorganicbuffer layer between the first emission layer and the first holetransport layer and the second inorganic buffer layer between the secondemission layer and the second hole transport layer may each serve as anelectron trap layer and/or a hole injection layer. Such a hole injectionlayer may include an alkali metal iodide and/or an alkali earth metaliodide, each having high reactivity, a wide band gap, and strong dipolecharacteristics, in order to increase hole injection efficiencyassociated with blocking of electrons, trapping of outgassing elements,and tunneling of dipole layers (e.g., dipole layer-induced enhancementof hole tunneling effects). Accordingly, the organic light-emittingdevice 10 may have increased efficiency and high reliability.

The organic layer included in the first emission unit may furtherinclude a first hole transport region between the first electrode 110and the first emission layer and a first electron transport regionbetween the first emission layer and the first charge generation layer150. In some embodiments, the organic layer included in the secondemission unit may further include a second hole transport region betweenthe first charge generation layer 150 and the second emission layer anda second electron transport region between the second emission layer andthe second electrode 190.

The first hole transport region, the first emission layer, the firstelectron transport region, the second hole transport region, the secondemission layer, and the second electron transport region will bedescribed in more detail.

The first and second hole transport regions may each include at leastone layer selected from a hole injection layer (HIL), a hole transportlayer (HTL), a buffer layer, and an electron blocking layer (EBL). Thefirst and second electron transport regions may each include at leastone layer selected from a hole blocking layer (HBL), an electrontransport layer (ETL), and an electron injection layer (EIL). However,embodiments of the layers are not limited thereto.

The first and second hole transport regions may each have a single-layerstructure including a single material, a single-layer structureincluding a plurality of different materials, or a multi-layer structureincluding a plurality of layers formed of a plurality of differentmaterials.

For example, the first and second hole transport regions may each have asingle-layer structure including a plurality of different materials, astructure of HIL/HTL, a structure of HIL/HTL/buffer layer, a structureof HIL/buffer layer, a structure of HTL/buffer layer, or a structure ofHIL/HTL/EBL, wherein layers of each structure are sequentially stackedin each stated order on the first electrode 110. However, embodiments ofthe structure are not limited thereto.

When the first and second hole transport regions each include an HIL,the HIL may be formed on the first electrode 110 using one or moresuitable methods selected from vacuum deposition, spin coating, casting,a Langmuir-Blodgett (LB) method, ink-jet printing, laser-printing, andlaser-induced thermal imaging (LITI).

When the HIL is formed by vacuum deposition, the vacuum deposition maybe performed at a deposition temperature of about 100° C. to about 500°C., a vacuum degree of about 10⁻⁸ torr to about 10⁻³ torr, and adeposition rate of about 0.01 Å/sec to about 100 Å/sec, depending on thecompound to be deposited in the HIL and the structure of the desiredHIL.

When the HIL is formed by spin coating, the spin coating may beperformed at a coating rate of about 2,000 rpm to about 5,000 rpm and ata heat treatment temperature of about 80° C. to about 200° C., dependingon the compound to be deposited in the HIL and the structure of thedesired HIL.

When the first and second hole transport regions each include an HTL,the HTL may be formed on the first electrode 110 or on the HIL using oneor more suitable methods selected from vacuum deposition, spin coating,casting, an LB method, ink-jet printing, laser-printing, and LITI. Whenthe HTL is formed by vacuum deposition and/or spin coating, thedeposition and coating conditions may be similar to the conditions usedfor forming the HIL.

The first and second hole transport regions may each include, forexample, at least one selected from m-MTDATA, TDATA, 2-TNATA, NPB,β-NPB, TPD, Spiro-TPD, Spiro-NPB, methylated NPB, TAPC, HMTPD,4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA),polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/camphor sulfonic acid (PANI/CSA),polyaniline/poly(4-styrenesulfonate) (PANI/PSS), a compound representedby Formula 201, and a compound represented by Formula 202:

In Formulae 201 and 202,

L₂₀₁ to L₂₀₅ may each be independently selected from a substituted orunsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xa1 to xa4 may each be independently selected from 0, 1, 2, and 3,

xa5 may be selected from 1, 2, 3, 4, and 5, and

R₂₀₁ to R₂₀₄ may each be independently selected from a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group.

For example, in Formulae 201 and 202,

L₂₀₁ to L₂₀₅ may each be independently selected from the groupconsisting of:

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorene group, a dibenzofluorenegroup, a phenanthrenylene group, an anthracenylene group, a pyrenylenegroup, a chrysenylene group, a pyridinylene group, a pyrazinylene group,a pyrimidinylene group, a pyridazinylene group, a quinolinylene group,an isoquinolinylene group, a quinoxalinylene group, a quinazolinylenegroup, a carbazolylene group, a triazinylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a pyrenylene group, a chrysenylene group, a pyridinylene group, apyrazinylene group, a pyrimidinylene group, a pyridazinylene group, aquinolinylene group, an isoquinolinylene group, a quinoxalinylene group,a quinazolinylene group, a carbazolylene group, and a triazinylenegroup, each substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an aminogroup, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkylgroup, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a pyrenyl group, achrysenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinylgroup, a pyridazinyl group, an isoindolyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, acarbazolyl group, and a triazinyl group,

xa1 to xa4 may each be independently selected from 0, 1, and 2,

xa5 may be selected from 1, 2, and 3, and

R₂₀₁ to R₂₀₄ may each be independently selected from the groupconsisting of:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, apyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group,a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, acarbazolyl group, a triazinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, apyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group,a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, acarbazolyl group, and a triazinyl group, each substituted with at leastone selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amino group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid group or a salt thereof, asulfonic acid group or a salt thereof, a phosphoric acid group or a saltthereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, abiphenyl group, a terphenyl group, a naphthyl group, an azulenyl group,a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, apyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group,a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, acarbazolyl group, and a triazinyl group, but embodiments of the presentdisclosure are not limited thereto.

The compound represented by Formula 201 may be represented by Formula201 Å:

For example, the compound represented by Formula 201 may be representedby Formula 201 Å-1, but embodiments of the present disclosure are notlimited thereto:

The compound represented by Formula 202 may be represented by Formula202 Å, but embodiments of the present disclosure are not limitedthereto:

In Formulae 201 Å, 201 Å-1, and 202 Å, L₂₀₁ to L₂₀₃, xa1 to xa3, xa5,and R₂₀₂ to R₂₀₄ may each be the same as described herein in connectionwith Formula 201, R₂₁₁ and R₂₁₂ may each be the same as described hereinin connection with R₂₀₃, and R₂₁₃ to R₂₁₇ may each be independentlyselected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group,a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group.

The compound represented by Formula 201 and the compound represented byFormula 202 may each independently be or include one selected fromCompounds HT1 to HT20, but embodiments of the present disclosure are notlimited thereto:

The thickness of each of the first and second hole transport regions maybe about 100 Å to about 10,000 Å, and in some embodiments, about 100 Åto about 1,000 Å. When the first and second hole transport regions eachinclude at least one selected from an HIL and an HTL, the thickness ofthe HIL may be about 100 Å to about 10,000 Å, and in some embodiments,about 100 Å to about 1,000 Å. The thickness of the HTL may be about 50 Åto about 2,000 Å, and in some embodiments, about 100 Å to about 1,500 Å.When the thicknesses of the first and second hole transport regions, theHIL, and the HTL are within these ranges, satisfactory hole transportingcharacteristics may be obtained without a substantial increase indriving voltage.

The first and second hole transport regions may each further include, inaddition to these materials, a charge-generation material for theimprovement of conductive properties. The charge-generation material maybe homogeneously or non-homogeneously dispersed in each of the first andsecond hole transport regions.

The charge-generation material may be, for example, a p-dopant. Thep-dopant may be one selected from a quinone derivative, a metal oxide,and a cyano group-containing compound, but embodiments of thecharge-generation material are not limited thereto. Non-limitingexamples of the p-dopant may include a quinone derivative (such astetracyanoquinonedimethane (TCNQ) and/or2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ)); ametal oxide (such as a tungsten oxide and/or a molybdenum oxide); and acyano group-containing compound, (such as Compound HT-D1), butembodiments of the p-dopant are not limited thereto:

The first and second hole transport regions may each further include, inaddition to the HIL and the HTL described above, at least one selectedfrom a buffer layer and an electron blocking layer (EBL). The bufferlayer may compensate for an optical resonance distance according to awavelength of light emitted from the emission layer (e.g., be used toadjust the optical resonance distance to match the wavelength of lightemitted from the emission layer), and thus, the efficiency of a formedorganic light-emitting device may be improved. Any suitable materialutilized in the first and second hole transport regions may also beincluded in the buffer layer. The EBL may prevent or reduce diffusiveloss of electrons to the first and second electron transport regions.

The first and second emission layers may be formed on the firstelectrode 110 or on the first and second hole transport regions usingone or more suitable methods selected from vacuum deposition, spincoating, casting, an LB method, ink-jet printing, laser-printing, andLITI. When the first and second emission layers are formed by vacuumdeposition and/or spin coating, the deposition and coating conditionsmay be similar to the conditions used for forming the HIL.

When the organic light-emitting device 10 is a full-color organiclight-emitting device, the first and second emission layers may each bepatterned into a red emission layer, a green emission layer, and a blueemission layer according to each individual sub-pixel. Alternatively,the first and second emission layers may each have a multi-layerstructure in which a red emission layer, a green emission layer, and ablue emission layer are stacked on one other, or a structure in which ared-light emitting material, a green-light emitting material, and ablue-light emitting material are mixed in the same layer to thereby emitwhite light.

The first and second emission layers may each include a host and adopant.

The host may include at least one selected from TPBi, TBADN, ADN (alsoreferred to as “DNA”), CBP, CDBP, and TCP:

Alternatively, the host may include a compound represented by Formula301:

Ar₃₀₁-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb2).  Formula 301

In Formula 301,

Ar₃₀₁ may be selected from the group consisting of:

a naphthalene, a heptalene, a fluorenene, a spiro-fluorene, abenzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, ananthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, anaphthacene, a picene, a perylene, a pentaphene, an indenoanthracene;and

a naphthalene, a heptalene, a fluorene, a spiro-fluorene, abenzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, ananthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, anaphthacene, a picene, a perylene, a pentaphene, and anindenoanthracene, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid group or a salt thereof, a sulfonic acid groupor a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkylgroup, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, aC₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, aC₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclicgroup, a monovalent non-aromatic condensed heteropolycyclic group, and—Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃) (where Q₃₀₁ to Q₃₀₃ may each be independentlyselected from hydrogen, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₆-C₆₀ aryl group, and a C₁-C₆₀ heteroaryl group),

L₃₀₁ may be the same as described herein in connection with L₂₀₁,

R₃₀₁ may be selected from the group consisting of:

a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a phenyl group, a biphenyl group, a terphenylgroup, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a pyrenyl group, a chrysenyl group, a pyridinylgroup, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, aquinolinyl group, an isoquinolinyl group, a quinoxalinyl group, aquinazolinyl group, a carbazolyl group, and a triazinyl group;

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, apyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group,a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, acarbazole group, a triazinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, apyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group,a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, acarbazole group, and a triazinyl group, each substituted with at leastone selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amino group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid group or a salt thereof, asulfonic acid group or a salt thereof, a phosphoric acid group or a saltthereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, abiphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group,a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a pyrenyl group, achrysenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinylgroup, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group,a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, and atriazinyl group,

xb1 may be selected from 0, 1, 2, and 3, and

xb2 may be selected from 1, 2, 3, and 4.

For example, in Formula 301,

L₃₀₁ may be selected from the group consisting of:

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-fluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a pyrenylene group, a chrysenylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-fluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a pyrenylene group, and a chrysenylene group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aphenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, apyrenyl group, and a chrysenyl group, and

R₃₀₁ may be selected from the group consisting of:

a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a phenyl group, a biphenyl group, a terphenylgroup, a naphthyl group, a fluorenyl group, a spiro-fluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a pyrenyl group, and a chrysenyl group;

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, apyrenyl group, a chrysenyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, apyrenyl group, and a chrysenyl group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amino group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid group or a salt thereof, asulfonic acid group or a salt thereof, a phosphoric acid group or a saltthereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, abiphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group,a spiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a pyrenyl group, anda chrysenyl group; but embodiments of the present disclosure are notlimited thereto.

For example, the host may include a compound represented by Formula 301Å:

In Formula 301 Å, the substituents may each be the same as describedherein in connection with Formula 301.

The compound represented by Formula 301 may be or include at least oneselected from Compounds H1 to H42, but embodiments of the presentdisclosure are not limited thereto:

Alternatively, the host may be or include at least one selected fromCompounds H43 to H49, but embodiments of the present disclosure are notlimited thereto:

The dopant may include at least one selected from a fluorescent dopantand a phosphorescent dopant.

For example, the phosphorescent dopant may include an organometalliccompound including one selected from iridium (Ir), platinum (Pt), osmium(Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu),terbium (Tb), thulium (Tm), Rh (rhodium), and Cu.

For another example, the phosphorescent dopant may include anorganometallic complex represented by Formula 401:

In Formula 401,

M may be selected from iridium (Ir), platinum (Pt), osmium (Os),titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium(Tb), and thulium (Tm),

X₄₀₁ to X₄₀₄ may each be independently selected from nitrogen (N) andcarbon (C),

ring A₄₀₁ and ring A₄₀₂ may each be independently selected from asubstituted or unsubstituted benzene, a substituted or unsubstitutednaphthalene, a substituted or unsubstituted fluorene, a substituted orunsubstituted spiro-fluorene, a substituted or unsubstituted indene, asubstituted or unsubstituted pyrrole, a substituted or unsubstitutedthiophene, a substituted or unsubstituted furan, a substituted orunsubstituted imidazole, a substituted or unsubstituted pyrazole, asubstituted or unsubstituted thiazole, a substituted or unsubstitutedisothiazole, a substituted or unsubstituted oxazole, a substituted orunsubstituted isoxazole, a substituted or unsubstituted pyridine, asubstituted or unsubstituted pyrazine, a substituted or unsubstitutedpyrimidine, a substituted or unsubstituted pyridazine, a substituted orunsubstituted quinoline, a substituted or unsubstituted isoquinoline, asubstituted or unsubstituted benzoquinoline, a substituted orunsubstituted quinoxaline, a substituted or unsubstituted quinazoline, asubstituted or unsubstituted carbazole, a substituted or unsubstitutedbenzoimidazole, a substituted or unsubstituted benzofuran, a substitutedor unsubstituted benzothiophene, a substituted or unsubstitutedisobenzothiophene, a substituted or unsubstituted benzoxazole, asubstituted or unsubstituted isobenzoxazole, a substituted orunsubstituted triazole, a substituted or unsubstituted oxadiazole, asubstituted or unsubstituted triazine, a substituted or unsubstituteddibenzofuran, and a substituted or unsubstituted dibenzothiophene,

at least one substituent of the substituted benzene, the substitutednaphthalene, the substituted fluorene, the substituted spiro-fluorene,the substituted indene, the substituted pyrrole, the substitutedthiophene, the substituted furan, the substituted imidazole, thesubstituted pyrazole, the substituted thiazole, the substitutedisothiazole, the substituted oxazole, the substituted isoxazole, thesubstituted pyridine, the substituted pyrazine, the substitutedpyrimidine, the substituted pyridazine, the substituted quinoline, thesubstituted isoquinoline, the substituted benzoquinoline, thesubstituted quinoxaline, the substituted quinazoline, the substitutedcarbazole, the substituted benzoimidazole, the substituted benzofuran,the substituted benzothiophene, the substituted isobenzothiophene, thesubstituted benzoxazole, the substituted isobenzoxazole, the substitutedtriazole, the substituted oxadiazole, the substituted triazine, thesubstituted dibenzofuran, and the substituted dibenzothiophene may beselected from the group consisting of:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid group or a salt thereof, a sulfonic acid groupor a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a heterocycloalkenyl group, a C₆-C₆₀ aryl group, aC₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroarylgroup, a monovalent non-aromatic condensed polycyclic group, amonovalent non-aromatic condensed heteropolycyclic group,—N(Q₄₀₁)(Q₄₀₂), —Si(Q₄₀₃)(Q₄₀₄)(Q₄₀₅), and —B(Q₄₀₆)(Q₄₀₇);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidgroup or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, aC₆-C₆₀aryloxy group, a C₆-C₆₀arylthio group, a C₁-C₆₀ heteroaryl group,a monovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —N(Q₄₁₁)(Q₄₁₂),—Si(Q₄₁₃)(Q₄₁₄)(Q₄₁₅), and —B(Q₄₁₆)(Q₄₁₇),

—N(Q₄₂₁)(Q₄₁₂), —Si(Q₄₁₃)(Q₄₁₄)(Q₄₁₅), and —B(Q₄₁₆)(Q₄₁₇),

L₄₀₁ may be an organic ligand,

xc1 may be selected from 1, 2, and 3, and

xc2 may be selected from 0, 1, 2, and 3.

Q₄₀₁ to Q₄₀₇, Q₄₁₁ to Q₄₁₇, and Q₄₂₁ to Q₄₂₇ may each be the same asdescribed herein in connection with Q₁.

L₄₀₁ may be selected from a monovalent organic ligand, a divalentorganic ligand, or a trivalent organic ligand. For example, L₄₀₁ may bea halogen ligand (e.g., CI and/or F), a diketone ligand (e.g.,acetylacetonate, 1,3-diphenyl-1,3-propane dionate,2,2,6,6-tetramethyl-3,5-heptanedionate, and/or hexafluoroacetonate), acarboxylic acid ligand (e.g., picolinate,dimethyl-3-pyrazolecarboxylate, and/or benzoate), a carbon monoxideligand, an isonitrile ligand, a cyano group ligand, or a phosphorusligand (e.g., phosphine and/or phosphite), but embodiments of thepresent disclosure are not limited thereto.

When ring A₄₀₁ in Formula 401 includes two or more substituents, thesubstituents may be linked (e.g., coupled) to each other to form asaturated or unsaturated ring.

When ring A₄₀₂ in Formula 401 includes two or more substituents, thesubstituents may be linked (e.g., coupled) to each other to form asaturated or unsaturated ring.

When xc1 in Formula 401 is two or more, a plurality of ligands may beidentical to or different from each other. When xc1 in Formula 401 istwo or more, ring A₄₀₁ and ring A₄₀₂ may each be directly connected(e.g., by a bond) or connected via a linking group (e.g., a C₁-C₅alkylene group, —N(R′)— (where R′ may be a C₁-C₁₀ alkyl group or aC₆-C₂₀ aryl group), and/or —C(═O)—) to A₄₀₁ and A₄₀₂, respectively, ofanother adjacent ligand.

The phosphorescent dopant may include at least one selected fromCompounds PD1 to PD74, but embodiments of the present disclosure are notlimited thereto:

In one embodiment, the phosphorescent dopant may include PtOEP:

The fluorescent dopant may include at least one selected from DPVBi,DPAVBi, TBPe, DCM, DCJTB, Coumarin 6, and C545T:

Alternatively, the fluorescent dopant may include a compound representedby Formula 501:

In Formula 501,

Ar₅₀₁ may be selected from the group consisting of:

a naphthalene, a heptalene, a fluorenene, a spiro-fluorene, abenzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, ananthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, anaphthacene, a picene, a perylene, a pentaphene, an indenoanthracene;and

a naphthalene, a heptalene, a fluorene, a spiro-fluorene, abenzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, ananthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, anaphthacene, a picene, a perylene, a pentaphene, and anindenoanthracene, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid group or a salt thereof, a sulfonic acid groupor a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkylgroup, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, aC₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, aC₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclicgroup, a monovalent non-aromatic condensed heteropolycyclic group, and—Si(Q₅₀₁)(Q₅₀₂)(Q₅₀₃) (where Q₅₀₁ to Q₅₀₃ may each be independentlyselected from hydrogen, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₆-C₆₀ aryl group, and a C₂-C₆₀ heteroaryl group),

L₅₀₁ to L₅₀₃ may each be the same as described herein in connection withL₂₀₁,

R₅₀₁ and R₅₀₂ may each be independently selected from the groupconsisting of:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, apyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group,a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, acarbazole group, a triazinyl group, a dibenzofuranyl group, adibenzothiophenyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, apyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group,a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, acarbazolyl group, a triazinyl group, a dibenzofuranyl group, and adibenzothiophenyl group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, aspiro-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group,a phenanthrenyl group, an anthracenyl group, a pyrenyl group, achrysenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinylgroup, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group,a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, atriazinyl group, a dibenzofuranyl group, and a dibenzothiophenyl group,

xd1 to xd3 may each be independently selected from 0, 1, 2, and 3, and

xd4 may be selected from 1, 2, 3, and 4.

The fluorescent dopant may be represented by at least one selected fromCompounds FD1 to FD9:

The amount of the dopant included in the first and second emissionlayers may be about 0.01 to about 15 parts by weight based on about 100parts by weight of the host, but embodiments of the present disclosureare not limited thereto.

The thickness of each of the first and second emission layers may beabout 100 Å to about 1,000 Å, and in some embodiments, about 200 Å toabout 600 Å. When the thickness of each of the first and second emissionlayers is within these ranges, excellent light-emission characteristicsmay be obtained without a substantial increase in driving voltage.

The first and second electron transport regions may be on the first andsecond emission layers, respectively.

The first and second electron transport regions may each include atleast one selected from an HBL, an ETL, and an EIL, but embodiments ofthe layers are not limited thereto.

For example, the first and second electron transport regions may eachhave a structure of ETL/EIL or a structure of HBL/ETL/EIL, whereinlayers are sequentially stacked in each stated order on the first andsecond emission layers.

In one or more embodiments, in the organic light-emitting device 10, thefirst emission unit may further include a first electron transportregion between the first emission layer and the first charge generationlayer, and the second emission unit may further include a secondelectron transport region between the second emission layer and thesecond electrode.

When the first and second electron transport regions each include anHBL, the HBL may be formed on the first and second emission layers usingone or more suitable methods selected from vacuum deposition, spincoating, casting, an LB method, ink-jet printing, laser-printing, andLITI. When the HBL is formed by vacuum deposition and/or spin coating,the deposition conditions and coating conditions may be similar to theconditions used for forming the HIL.

The HBL may include, for example, at least one selected from BCP andBphen, but embodiments of the present disclosure are not limitedthereto.

The thickness of the HBL may be about 20 Å to about 1,000 Å, and in someembodiments, about 30 Å to about 300 Å. When the thickness of the HBL iswithin these ranges, excellent hole blocking characteristics may beobtained without a substantial increase in driving voltage.

The first and second electron transport regions may each include an ETL.The ETL may be formed on the first and second emission layers using oneor more suitable methods selected from vacuum deposition, spin coating,casting, an LB method, ink-jet printing, laser-printing, and LITI. Whenthe ETL is formed by vacuum deposition and/or spin coating, thedeposition conditions and coating conditions may be similar to theconditions used for forming the HIL.

The ETL may include at least one selected from a compound represented byFormula 601 and a compound represented by Formula 602:

Ar₆₀₁-[(L₆₀₁)_(xe1)-E₆₀₁]_(xe2).  Formula 601

In Formula 601,

Ar₆₀₁ may be selected from the group consisting of:

a naphthalene, a heptalene, a fluorenene, a spiro-fluorene, abenzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, ananthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, anaphthacene, a picene, a perylene, a pentaphene, an indenoanthracene;and

a naphthalene, a heptalene, a fluorene, a spiro-fluorene, abenzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, ananthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, anaphthacene, a picene, a perylene, a pentaphene, and anindenoanthracene, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazine group, a hydrazonegroup, a carboxylic acid group or a salt thereof, a sulfonic acid groupor a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkylgroup, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, aC₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, aC₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclicgroup, a monovalent non-aromatic condensed heteropolycyclic group, and—Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃) (where Q₃₀₁ to Q₃₀₃ may each be independentlyselected from hydrogen, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₆-C₆₀ aryl group, or a C₂-C₆₀ heteroaryl group),

L₆₀₁ may be the same as described herein in connection with L₂₀₁,

E₆₀₁ may be selected from the group consisting of:

a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolylgroup, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, anoxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a purinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a carbazolyl group, a phenanthridinyl group, anacridinyl group, a phenanthrolinyl group, a phenazinyl group, abenzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, anisobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group,a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a dibenzofuranyl group, a dibenzothiophenyl group, abenzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinylgroup, an imidazopyrimidinyl group; and

a pyrrolyl group, a thiophenyl group, a furanyl group, an imidazolylgroup, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, anoxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a purinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a carbazolyl group, a phenanthridinyl group, anacridinyl group, a phenanthrolinyl group, a phenazinyl group, abenzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, anisobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group,a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a dibenzofuranyl group, a dibenzothiophenyl group, abenzocarbazolyl group, a dibenzocarbazolyl group, an imidazopyridinylgroup, and an imidazopyrimidinyl group, each substituted with at leastone selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amino group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid group or a salt thereof, asulfonic acid group or a salt thereof, a phosphoric acid group or a saltthereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, abiphenyl group, a terphenyl group, a pentalenyl group, an indenyl group,a naphthyl group, an azulenyl group, a heptalenyl group, an indacenylgroup, an acenaphthyl group, a fluorenyl group, a spiro-fluorenyl group,a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, aphenanthrenyl group, an anthracenyl group, a fluoranthenyl group, atriphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenylgroup, a picenyl group, a perylenyl group, a pentaphenyl group, ahexacenyl group, a pentacenyl group, a rubicenyl group, a coronenylgroup, an ovalenyl group, a pyrrolyl group, a thiophenyl group, afuranyl group, an imidazolyl group, a pyrazolyl group, a thiazolylgroup, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, apyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, an isoindolyl group, an indolyl group, an indazolyl group, apurinyl group, a quinolinyl group, an isoquinolinyl group, abenzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, acarbazolyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, abenzofuranyl group, a benzothiophenyl group, an isobenzothiazolyl group,a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an oxadiazolyl group, a triazinyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, an imidazopyridinyl group, and animidazopyrimidinyl group,

xe1 may be selected from 0, 1, 2, and 3, and

xe2 may be selected from 1, 2, 3, and 4.

In Formula 602,

X₆₁₁ may be selected from N and C-(L₆₁₁)_(xe611)-R₆₁₁, X₆₁₂ may beselected from N and C-(L₆₁₂)_(xe612)-R₆₁₂, and X₆₁₃ may be selected fromN and C-(L₆₁₃)_(xe613)-R₆₁₃, wherein at least one selected from X₆₁₁ toX₆₁₃ may be N,

L₆₁₁ to L₆₁₆ may each be the same as described herein in connection withL₂₀₁,

R₆₁₁ to R₆₁₆ may each be independently selected from the groupconsisting of:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, apyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group,a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, acarbazolyl group, a triazinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, apyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group,a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, acarbazolyl group, and a triazinyl group, each substituted with at leastone selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amino group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid group or a salt thereof, asulfonic acid group or a salt thereof, a phosphoric acid group or a saltthereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, abiphenyl group, a terphenyl group, a naphthyl group, an azulenyl group,a fluorenyl group, a spiro-fluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, apyrenyl group, a chrysenyl group, a pyridinyl group, a pyrazinyl group,a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, anisoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, acarbazolyl group, and a triazinyl group, and

xe611 to xe616 may each be independently selected from 0, 1, 2, and 3.

The compound represented by Formula 601 and the compound represented byFormula 602 may each be independently selected from Compounds ET1 toET15:

Alternatively, the ETL may include at least one selected from BCP,Bphen, Alq₃, Balq, TAZ, and NTAZ below:

The thickness of the ETL may be about 100 Å to about 1,000 Å, and insome embodiments, about 150 Å to about 500 Å. When the thickness of theETL is within these ranges, satisfactory electron transportingcharacteristics may be obtained without a substantial increase indriving voltage.

The ETL may further include, in addition to these materials, ametal-containing material.

The metal-containing material may include a Li complex. The Li complexmay include, for example, Compound ET-D1 (lithium quinolate (LiQ))and/or ET-D2:

The first and second electron transport regions may each include anelectron injection layer (EIL) to facilitate electron injection from thesecond electrode 190.

The EIL may be formed on the ETL using one or more suitable methodsselected from vacuum deposition, spin coating, casting, an LB method,ink-jet printing, laser-printing, and LITI. When the EIL is formed byvacuum deposition and/or spin coating, the deposition conditions andcoating conditions may be similar to the conditions used for forming theHIL.

The EIL may include at least one selected from LiF, NaCl, CsF, Li₂O,BaO, and LiQ.

The thickness of the EIL may be about 1 Å to about 100 Å, and in someembodiments, about 3 Å to about 90 Å. When the thickness of the EIL iswithin these ranges, satisfactory electron injecting characteristics maybe obtained without a substantial increase in driving voltage.

The second electrode 190 may be a cathode, which is an electroninjection electrode. The material for forming the second electrode 190may be selected from a metal, an alloy, an electrically conductivecompound, and combinations thereof, each having a relatively low workfunction. Non-limiting examples of the material for forming the secondelectrode 190 may include Li, Mg, Al, Al—Li, Ca, Mg—In, and Mg—Ag. Insome embodiments, the second electrode 190 may be a semi-transmissiveelectrode or a transmissive electrode, and the material for forming thesecond electrode 190 may include ITO or IZO.

Hereinbefore, the organic light-emitting device 10 has been describedwith reference to the drawing, but embodiments of the present disclosureare not limited thereto.

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear orbranched aliphatic hydrocarbon monovalent group having 1 to 60 carbonatoms, and non-limiting examples thereof may include a methyl group, anethyl group, a propyl group, an isobutyl group, a sec-butyl group, ater-butyl group, a pentyl group, an iso-amyl group, and a hexyl group.The term “C₁-C₅ alkylene group” as used herein refers to a divalentgroup having substantially the same structure as the C₁-C₅ alkyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalentgroup represented by —O-A₁₀₁ (where A₁₀₁ is a C₁-C₆₀ alkyl group), andnon-limiting examples thereof may include a methoxy group, an ethoxygroup, and an isopropyloxy group.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a hydrocarbongroup formed by substituting at least one carbon-carbon double bond inthe body (e.g., middle) or at the terminus of the C₂-C₆₀ alkyl group,and non-limiting examples thereof may include an ethenyl group, apropenyl group, and a butenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a hydrocarbongroup having at least one carbon-carbon triple bond in the body (e.g.,middle) or at the terminus of the C₂-C₆₀ alkyl group, and non-limitingexamples thereof may include an ethynyl group and a propynyl group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalentsaturated hydrocarbon monocyclic group having 3 to 10 carbon atoms, andnon-limiting examples thereof may include a cyclopropyl group, acyclobutyl group, a cyclopentyl group, a cyclohexyl group, and acycloheptyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to amonovalent monocyclic group having at least one heteroatom selected fromN, O, Si, P, and S as a ring-forming atom in addition to 1 to 10 carbonatoms, and non-limiting examples thereof may include a tetrahydrofuranylgroup and a tetrahydrothiophenyl group.

The term “C₃-C₁₀ cycloalkenyl group” as used herein refers to amonovalent monocyclic group that has 3 to 10 carbon atoms and at leastone double bond in the ring thereof, and does not have aromaticity.Non-limiting examples thereof may include a cyclopentenyl group, acyclohexenyl group, and a cycloheptenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein refers to amonovalent monocyclic group that has at least one heteroatom selectedfrom N, O, Si, P, and S as a ring-forming atom, 1 to 10 carbon atoms,and at least one double bond in its ring. Non-limiting examples of theC₁-C₁₀ heterocycloalkenyl group may include a 2,3-hydrofuranyl group anda 2,3-hydrothiophenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent grouphaving a carbocyclic aromatic system having 6 to 60 carbon atoms, andthe term “C₆-C₆₀ arylene group” as used herein refers to a divalentgroup having a carbocyclic aromatic system having 6 to 60 carbon atoms.Non-limiting examples of the C₆-C₆₀ aryl group may include a phenylgroup, a naphthyl group, an anthracenyl group, a phenanthrenyl group, apyrenyl group, and a chrysenyl group.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalentcarbocyclic aromatic system having at least one heteroatom selected fromN, O, Si, P, and S as a ring-forming atom in addition to 1 to 60 carbonatoms. Non-limiting examples of the C₁-C₆₀ heteroaryl group may includea pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, and an isoquinolinylgroup. When the C₁-C₆₀ heteroaryl group includes two or more rings, therings may be fused (e.g., coupled) to each other.

The term “C₆-C₆₀ aryloxy group” as used herein refers to a grouprepresented by —O-A₁₀₂ (where A₁₀₂ is a C₆-C₆₀ aryl group), and the term“C₆-C₆₀ arylthio group” as used herein refers to a group represented by—S-A₁₀₃ (where A₁₀₃ is a C₆-C₆₀ aryl group).

The term “monovalent non-aromatic condensed polycyclic group” as usedherein refers to a monovalent group that has two or more rings condensed(e.g., coupled) to each other, only carbon atoms as a ring forming atom,and non-aromaticity in the entire molecular structure. A non-limitingexample of the monovalent non-aromatic condensed polycyclic group may bea fluorenyl group.

The term “monovalent non-aromatic condensed heteropolycyclic group” asused herein refers to a monovalent group that has two or more ringscondensed to each other, has a heteroatom selected from N, O, Si, P, andS in addition to carbon atoms as ring forming atoms, and hasnon-aromaticity in the entire molecular structure. A non-limitingexample of the monovalent non-aromatic condensed heteropolycyclic groupmay be a carbazolyl group.

An organic light-emitting device according to embodiments of the presentdisclosure may have high efficiency and long lifespan.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments.

The use of “may” when describing embodiments of the present disclosurerefers to “one or more embodiments of the present disclosure”. Inaddition, as used herein, the terms “use”, “using”, and “used” may beconsidered synonymous with the terms “utilize”, “utilizing”, and“utilized”, respectively.

As used herein, the terms “substantially”, “about”, and similar termsare used as terms of approximation and not as terms of degree, and areintended to account for the inherent deviations in measured orcalculated values that would be recognized by those of ordinary skill inthe art.

Also, any numerical range recited herein is intended to include allsubranges of the same numerical precision subsumed within the recitedrange. For example, a range of “1.0 to 10.0” is intended to include allsubranges between (and including) the recited minimum value of 1.0 andthe recited maximum value of 10.0, that is, having a minimum value equalto or greater than 1.0 and a maximum value equal to or less than 10.0,such as, for example, 2.4 to 7.6. Any maximum numerical limitationrecited herein is intended to include all lower numerical limitationssubsumed therein and any minimum numerical limitation recited in thisspecification is intended to include all higher numerical limitationssubsumed therein. Accordingly, Applicant reserves the right to amendthis specification, including the claims, to expressly recite anysub-range subsumed within the ranges expressly recited herein.

While one or more embodiments have been described with reference to thedrawings, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope of the present disclosure, asdefined by the following claims and equivalents thereof.

What is claimed is:
 1. An organic light-emitting device comprising: afirst electrode; a second electrode facing the first electrode; a firstemission unit, a second emission unit and a third emission unit betweenthe first electrode and the second electrode; a first charge generationlayer between the first emission unit and the second emission unit; anda second charge generation layer between the second emission unit andthe third emission unit, wherein the first emission unit comprises afirst emission layer, the second emission unit comprises a secondemission layer, the third emission unit comprises a third emissionlayer, and at least one of the first emission unit, the second emissionunit and the third emission unit comprises an inorganic buffer layer. 2.The organic light-emitting device of claim 1, wherein the third emissionunit comprises the inorganic buffer layer.
 3. The organic light-emittingdevice of claim 1, wherein the third emission unit comprises a metalhalide.
 4. The organic light-emitting device of claim 3, wherein themetal halide is included in an inorganic buffer layer in the thirdemission unit.
 5. The organic light-emitting device of claim 3, whereinthe metal halide comprises at least one iodide compound selected fromthe group consisting of an alkali metal iodide, an alkaline earth metaliodide, a transition metal iodide, a post-transition metal iodide, and alanthanum-based metal iodide.
 6. The organic light-emitting device ofclaim 3, wherein the metal halide comprises at least one iodide compoundselected from the group consisting of a lithium (Li) iodide, a sodium(Na) iodide, a potassium (K) iodide, a rubidium (Rb) iodide, a cesium(Cs) iodide, a beryllium (Be) iodide, a magnesium (Mg) iodide, a calcium(Ca) iodide, a strontium (Sr) iodide, a barium (Ba) iodide, a ytterbium(Yb) iodide, a samarium (Sm) iodide, a copper (Cu) iodide, a thallium(TI) iodide, a silver (Ag) iodide, a cadmium (Cd) iodide, a mercury (Hg)iodide, a tin (Sn) iodide, a lead (Pb) iodide, a bismuth (Bi) iodide, azinc (Zn) iodide, a manganese (Mn) iodide, an iron (Fe) iodide, a cobalt(Co) iodide, a nickel (Ni) iodide, an aluminum (Al) iodide, an indium(In) iodide, a gallium (Ga) iodide, a thorium (Th) iodide, and a uranium(U) iodide.
 7. The organic light-emitting device of claim 3, wherein themetal halide comprises at least one iodide compound selected from thegroup consisting of LiI, NaI, KI, RbI, CsI, BeI₂, MgI₂, CaI₂, SrI₂,BaI₂, YbI, YbI₂, YbI₃, SmI₃, CuI, TlI, AgI, CdI₂, HgI₂, SnI₂, PbI₂,BiI₃, ZnI₂, MnI₂, FeI₂, CoI₂, NiI₂, AII₃, InI₃, GaI₃, ThI₄, and UI₃. 8.The organic light-emitting device of claim 1, wherein the inorganicbuffer layer has a thickness of 1 nm to 20 nm.
 9. An organiclight-emitting device comprising: a first electrode; a second electrodefacing the first electrode; and a first emission unit and a secondemission unit between the first electrode and the second electrode,wherein the first emission unit is arranged toward the first electrode,the second emission unit is arranged toward the second electrode, thefirst emission unit comprises a first emission layer, the secondemission unit comprises a second emission layer, and the first emissionunit and the second emission unit each comprise a metal halide.
 10. Theorganic light-emitting device of claim 9, wherein the metal halide isincluded in a first inorganic buffer layer in the first emission unitand a second inorganic buffer layer in the second emission unit.
 11. Theorganic light-emitting device of claim 10, wherein: the first inorganicbuffer layer is included in a first hole transport region between thefirst emission layer and the first electrode, and the second inorganicbuffer layer is included in a second hole transport region between thesecond emission layer and the first emission unit.
 12. The organiclight-emitting device of claim 11, wherein: the first inorganic bufferlayer is directly in contact with the first emission layer, and thesecond inorganic buffer layer is directly in contact with the secondemission layer.
 13. The organic light-emitting device of claim 10,wherein the first inorganic buffer layer and the second inorganic bufferlayer each further comprise at least one metal.
 14. The organiclight-emitting device of claim 10, wherein the first inorganic bufferlayer and the second inorganic buffer layer are each formed of the metalhalide.
 15. The organic light-emitting device of claim 9, wherein themetal halide comprises at least one iodide compound selected from thegroup consisting of an alkali metal iodide, an alkaline earth metaliodide, a transition metal iodide, a post-transition metal iodide, and alanthanum-based metal iodide.
 16. The organic light-emitting device ofclaim 9, wherein the metal halide comprises at least one iodide compoundselected from the group consisting of a lithium (Li) iodide, a sodium(Na) iodide, a potassium (K) iodide, a rubidium (Rb) iodide, a cesium(Cs) iodide, a beryllium (Be) iodide, a magnesium (Mg) iodide, a calcium(Ca) iodide, a strontium (Sr) iodide, a barium (Ba) iodide, a ytterbium(Yb) iodide, a samarium (Sm) iodide, a copper (Cu) iodide, a thallium(TI) iodide, a silver (Ag) iodide, a cadmium (Cd) iodide, a mercury (Hg)iodide, a tin (Sn) iodide, a lead (Pb) iodide, a bismuth (Bi) iodide, azinc (Zn) iodide, a manganese (Mn) iodide, an iron (Fe) iodide, a cobalt(Co) iodide, a nickel (Ni) iodide, an aluminum (Al) iodide, an indium(In) iodide, a gallium (Ga) iodide, a thorium (Th) iodide, and a uranium(U) iodide.
 17. The organic light-emitting device of claim 9, whereinthe metal halide comprises at least one iodide compound selected fromthe group consisting of LiI, NaI, KI, RbI, CsI, BeI₂, MgI₂, CaI₂, SrI₂,BaI₂, YbI, YbI₂, YbI₃, SmI₃, CuI, TlI, AgI, CdI₂, HgI₂, SnI₂, PbI₂,BiI₃, ZnI₂, MnI₂, FeI₂, CoI₂, NiI₂, AlI3, InI₃, GaI₃, ThI₄, and UI₃. 18.The organic light-emitting device of claim 9, further comprising a thirdemission unit between the second emission unit and the second electrode,wherein the third emission unit comprises a third emission layer and ametal halide.